The present invention relates to a housing for electrical equipment, particularly a switch having a housing body which can be pushed into an installation opening and a covering wall which extends across the installation opening, which is suitable for insertion into one of the installation openings of a switching panel.
Such housings are disclosed, for example, in F.R.G. Patent No. 2,928,277, which corresponds to U.S. Pat. No. 4,329,669 to Krasser et al. An essentially block-shaped housing body is inserted in an insertion direction from the front of a switching panel into an installation opening having a cross-sectional outline corresponding to that of the housing body. The housing includes a front cover wall connected to a housing body which extends transversely to the insertion direction and which has a collar which projects on all sides beyond the cross-sectional outline of the housing body so as to act as a limitation for the extent of insertion of the housing into the opening. In a final, installed position, the collar lies against a front surface region of the switching panel adjacent to the installation opening and covers it. The housing is fixed in the final installed position by means of resiliently deformable spreadable lugs which are attached to two opposed side walls of the housing body. The lugs project outwardly from the housing body at an acute angle which opens in a direction which is generally opposite to the insertion direction. The lugs have free ends which extend in a direction which is approximately parallel to the insertion direction and which have a toothed detent profile, each tooth of which can engage with a corresponding edge portion of the installation opening. Since the spreadable lugs are bent inwardly to be received in the installation opening when the housing body is pushed in, the inherent resiliency of the spreadable lugs creates an outwardly oriented spring force which secures the housing in the installation opening.
Problems arise with this prior art type of housing, since a firm seating of the housing in the installation opening is often not ensured over a wide range of switching panel thicknesses. For safety reasons, however, the attachment must be so strong that removal of the device from the switching panel is prevented regardless of the thickness of the switching panel, and wherein the housing can be removed only with the aid of special tools.